EY publishes the results of its Risks and Opportunities survey of mining executives around this time every year. While nobody is claiming that this is a scientifically rigorous survey, it nevertheless captures the mood of the sector and, as such, it’s important to reflect upon what’s being said.
How do the 2023 results compare with the past?
The table below lists the results from the Olympic cycle, starting with Rio de Janeiro (OK, Tokyo should have been in 2020).
It’s not the purpose here to review and comment on each line, but this is clearly a volatile list, even allowing for the evolution of terminology and overlap between similar terms.
Overall, the drive towards sustainable investment, human rights, transparency, wider recognition of the climate change emergency and mining’s role in providing those metals and minerals that are needed for the electrification of our societies, is unmissable.
If you work in the mining industry, or wish to, it makes sense to consider this list carefully. For example, the report that accompanies this survey talks in depth about the opportunities that machine learning and data science unlocks – so, even without any direct experience of mining, any skills that you have it this area could mean a large demand for your time.
ESG, as a theme, shines through
While a number of environmental, social and governance (ESG) issues have been present on the list for a few years, ESG did not appear as a term in its own right until 2022 (albeit without the G part that year). It has remained in the gold-medal slot ever since.
It is then useful to look at how ESG is further broken down in the survey responses…
When I read this year’s report, I was struck by how many of these ESG issues are affected by my area of expertise – solid-liquid separation in mineral processing. How about you?
Even though my first spreadsheet on how filter cake moisture affects greenhouse gas (GHG) production from fuel used for themal evaporation was written >20 years ago, I have only very recently started to appreciate mining sustainability as a topic in its own right.
What’s solid-liquid separation got to do with it?
It’s impossible to do more than give a few examples of how the fields of ESG and solid-liquid separation intersect, but…
Filtration can be used to produce stackable tailings (often known, misleadingly, as dry stacks) and almost particle-free water that can be reused or treated. This, in turn, can affect the top three issues from EY’s list directly – local community impact, tailings and waste management and water stewardship – not to mention green production and biodiversity.
Furthermore, such tailings storage can have a higher level of resilience to extreme climatic events. (Going deeper, however, while such stacks are less likely to collapse, they can generate more dust, having a negative, for example, on local community impact. It also has an effect on costs (see issue six on the main list.)
Filtration can be used to remove water from a mineral concentrate or waste slurry with fewer GHGs than thermal evaporation, having a positive impact on attaining net zero emissions and green production. This also applies to shipping (and, hence, costs on the main list again), especially where products or waste are shipped over long distances.
Using residues and wastes from one production process as a raw material for another (even in another industry) is at the core of circular economy. Removal of contaminants with filter cake washing if, say, they are held in the liquid, can be an essential step before shipping onward, mitigating some of the risk of a tailings storage facility (TSF) and even creating opportunities for revenue.
Filtration, and hence filtered tailings stacking, can enable progressive capping and revegetation of a TSF. We hold the vision that, on the day of mine closure, a mine manager will shut off the griding mills and, in the afternoon, stand for a publicity photo with the local media as they ceremoniously put the final shovel of tailings into the last remaining patch before placing the last piece of turf and planting a tree…
We could give many other examples, as, equally, could those practitioners working to improve grinding, flotation, physical separation, trucking, bio-remediation or implementing better social engagement, improving diversity and equalising opportunities.
The point being that this is a multi-layered issue; ESG to wider society depends in large part upon decarbonising human activity to halt climate change. Mining is the only viable path to the only possible solution we have to climate change – namely the production, storage, transmission and use of renewable power (wind, solar, nuclear, tidal, wave etc..).
This requires the mining and refining of metals and minerals in unprecedented quantities, and this activity can have a huge local impact on nature, people and communities, not to mention its own impact on GHG emissions.
Why tailings are worth another look
The EY report gives the figures of “200 billion tonnes of existing tailings under management and an additional 40 to 50 billion tonnes expected in the next five years”. Furthermore “Fifty-five percent of survey respondents expected tailings to receive investor attention, compared with fewer than 5% last year [2023]”.
A higher degree of solid-liquid separation through filtration prior to deposition will be a part of the solution, depending upon local conditions, size, water (surplus or deficit), geography, geology, topography and communities. Other approaches, such as paste thickening or Anglo American’s Hydraulic Dewatered Stacking (HDS), together with conventional tailings, where appropriate, all have their part to play.
Getting this right can provide a major step forward, while getting it wrong (through inappropriate technology, the wrong filter medium, poor operation etc.) can drastically compromise a company’s ESG credentials and even halt production and, hence, revenue.
Which is surely the biggest concern on the minds of all mining executives?
Dr. Trevor Sparks has worked in the solid-liquid separation space, in one form or another, living in many countries, for almost 30 years – with global filtration equipment and technology providers as well as end-users. He has spent a good portion of that time initiating a number of product innovations, from the small to the absolutely huge, that are out there working today, making mineral processing and metal production more successful and sustainable.
To continue the conversation, contact Trevor at Kipinat or via LinkedIn